Image-receiving material for color diffusion transfer process

ABSTRACT

An image-receiving material for color diffusion transfer processing is provided with a neutralization rate-controlling layer containing at least one polymer of the monomethacrylic or monoacrylic acid ester of a polyhydric alcohol.

United States Patent i [1 1 Yoshida et al.

'[ Nov. 12, 1974 221 Filed:

- 21 Appl. No.: 338,715

[ IMAGE-RECEIVING MATERIAL FOR COLOR DIFFUSION TRANSFER PROCESS 75Inventors: Takashi Yoshida: Shinji Sakaguchi:

Takushi Miyazako, all of Kanagawa, Japan [73] Assignee: Fuji Photo FilmCo., Ltd.,

Ashigara-shi, Kanagawa, Japan Mar. 7, 1973 [30] Foreign ApplicationPriority Data Mar, 7, I972 Japan 47-23466 52 Us. Cl. 96/77, 96/3 UX,96/119 R 51 Im. Cl G03C 1/40, 0030 7/00 [58] Field of Search..... 96/3,77, 76 R, 29 D, 119 R [56] References Cited UNITED STATES PATENTSPrimary E.raminerDavid Klein Assistant Examiner-Richard L. SchillingAttorney, Agent, or FirmSughrue, Rothwell. Mion, Zinn & Macpeak 14Claims, N0 Drawings.

l/l969 Taylor 96/3 BACKGROUND OF THE INVENTION 1. Field of the InventionThis invention relates to an image-receiving material for a colorphotographic diffusion transfer process, more specifically, it relatesto an image-receiving material for a color photographic diffusiontransfer process, which image-receiving material has an improved layerfor controlling the neutralization rate.

2. Description of the Prior Art In a general color photographicdiffusion transfer process, a color former such as a dye developer or adiffusible coupler type developer has been incorporated in a negativelight-sensitive layer together with a silver halide photographicemulsionand after exposing the negative light-sensitive emulsion layer,the negative layer is brought into contact with a positive layer with analkali processing agent between them, whereby the silver halidephotographic emulsion is developed and at the same time theabove-mentioned color former is diffused into the alkali processingagent and then transferred into the positive layer.

As the color former, an alkaline and water-insoluble material has beenmainly employed, but this type of color former is subject to the faultthat when the positive layer containing it is exposed to air after thetransfer is finished the material is oxidized to be decolored or to formstains. To prevent this, usually an acid poly mer layer forneutralization. is placed between the image-receiving layer and thesupport of the positive layer. That is to say, by placing the acidpolymer layer for neutralization between the two layers, the dye imagetransferred can be prevented from being oxidized and thus the occurenceof decoloring and the formation of stains are prevented.

However, if the neutralization of the alkaliprocessing agent by the acidpolymer layer for neutralization proceeds too fast, the color formerdiffuses in the alkali processing agent only with difficulty owing tothe reduction of pH, which results in lowering the efficiency of thediffusion transfer. Accordingly, it is necessary to control theneutralization rate or speed by further providing a polymer layer(hereinafter, this polymer layer is called a neutralizationrate-controlling layer in this specificationlbetween thedye'image-receiving layer and the acid polymer layer for neutralization.

It is described in U.S. Pat. No. 3,362,819 to employ I such aneutralization rate-controlling layer, the patent teaching the use of apolymer of polyvinyl alcohol, a partially acetalated polyvinyl alcoholor gelatin as the polymer for the neutralization rate-controlling layeras preferred. However, even when the polymer described in this patent isused for the neutralization ratecontrolling layer, a sufficient colordensity of formed images on the image-receiving layer is not obtainedsince the neutralization rate of the alkali processing agent is stilltoo high even in such a case.

SUMMARY OF THE INVENTION One object of this invention is, therefore, toprovide a polymer suitable for the neutralization ratecontrolling layerof an image-receiving layer.

2 transfer process capable of giving images having a high color densityand lowered stains.

As the result of various studies for attaining the DETAILED DESCRIPTIONOF THE INVENTION The image-receiving material for a color diffusiontransfer process of this invention fundamentally comprises a supporthaving thereon an acid polymer layer for neutralization, aneutralization rate-controlling layer and an image-receiving layercapable of mordanting dyes.

Examples of the support used in this invention are baryta-coated papers;laminate papers coated with a resin such as polyethylene polypropylene,and polystyrene; sheets of a cellulose organic acid ester such ascellulose diacetate, cellulose triacetate, cellulose butyrate, cellulosepropionate and cellulose acetate butyrate; sheets of an inorganic acidester such as cellulose nitrate; sheets of a polyester such aspolyethylene terephthalate; sheets of polyvinylacetals such as polyvinylI formal, polyvinyl butyral, polyvinyl acetal and polyvinyl benzal; andsheets of a polyalkylene such as polystyrene, polypropylene,polyethylene and polyvinyl chloride; polycarbonate, etc.

As the polymer for the acid polymer layer for neutralization of theimage-receiving material of this invention there can be used any polymerhaving one or more Another object of this invention is to provide animage-receiving layer for a color photographic diffusion carboxylgroups, sulfo groups or a group which changes to a carboxyl group byhydrolysis, and which has a filmforming property, includinghomopolymers, copolymers or graft polymers of vinylbenzenesulfonic acidand like materials. The acid polymer preferably has a molecular weightof from about 10,000 to about 100,000. For example, there may be usedthe monobutyl ester of a l l copolymer of maleic anhydride and themonobutyl ester of the l l copolymer of maleic anhydride and methylvinyl ether as described in the specification of U.S. Pat. No.3,362,819. Other examples of the polymer for the acid polymer layer forneutralization are the monoethyl ester, the monopropyl ester, themonopentyl ester and the monohexyl ester of the l l copolymer of maleicanhydride and ethylene; the monoethyl ester, the monopropyl ester, themonopentyl ester, and the monohexyl ester of the l 1 copolymer of maleicanhydride and methyl vinyl ether; polyacrylic acid; polymethacrylicacid; copolymers of acrylic acid and methacrylic acid in variouscomponent ratios; and copolymers of acrylic acid or methacrylic acid andother vinylic monomers in various component ratios, e.g., for example,acrylic esters, methacrylic esters, vinylethers and the like, suitablycontaining at least 30 molar percent of acrylic acid or methacrylicacid, and preferably from about 50 molar percent to about molar percentof acrylic acid or methacrylic acid. Such a polymer as mentioned aboveis usually dissolved in an alcohol such as methanol, ethanol, propa- 3nol and butanol; a ketone such as acetone, methyl ethyl ketone andcyclohexanone; an ester such as ethyl acetate and butyl acetate; or amixture of these solvents, and then applied on the support as asolution.

While a copolymerization ratio of l 1 is given above, this is merelyexemplary and a molar ratio of from from 100 to 0 100 can be used (atthe bounds of this range, one must be sure at least one carboxyl and/orsulfo group is present).

The thickness of the acid polymer layer thus formed cannot be definedgenerally since it is well varied according to the composition and theamount of the alkali processing agent used, but it is suitably -30microns.

The neutralization rate-controlling layer which is the most importantfeature of this invention will now be explained.

The polymer used in the neutralization ratecontrolling layer is analkali permeable and water permeable polymer. Practically speaking, thepolymer used in the neutralization rate-controlling layer is ahomopolymer, copolymer or graft polymer of a monomethacrylic acid esterand/or a monoacrylic acid ester of a polyhydric alcohol.

There is no particular limitation on the polyhydric alcohol used so longas the resulting polymer is alkali and water permeable. However,preferred polyhydric alcohols used in this invention, which can bealiphatic or aromatic in nature, can be defined as compounds having atleast two aliphatic hydroxy groups, preferably compounds having from 2to 5 aliphatic hydroxy groups, and having from 2 to 12 carbon atoms.There are, for example, diols such as polyethylene glycol, polyethyleneoxide, polypropylene oxide, polybutylene oxide, polycyclohexene oxide,polystyrene oxide, p0-

lyoxetane, polytetrahydrofuran, cyclohexane diol, xylhydroxypropylacrylate 4-hydroxybutyl acrylate, 5-

hydroxypentyl acrylate, 2,2-dimethyl-hydroxypropyl acrylate, diethyleneglycol monoacrylate, trimethylolpropane monoacrylate, pentaerythritolmonoacrylate and the like.

As comonomers used to form copolymers with the above-mentioned estersused in this invention, any

addition-polymerizable monomer can be used, with preferred monomersbeing those having a vinyl or vinylidene group. There are, for example,amides or esters (having 3-15 carbon atoms) of acrylic acid ormethacrylic acid, such as, acryl amide, methacrylamide,diacetoneacrylamide, acryloyl morpholine, alkyl acrylates andmethacrylates such as methyl methacrylate, ethyl methacrylate, propylacrylate, propyl methyacrylate, chloroethyl acrylate, chloroethylmethacrylate, butyl acrylate, pentyl methacrylate, hexyl acrylate andhexyl methacrylate, vinyl esters such as vinyl acetate, vinyl butyrate,vinyl propionate, vinyl benzoether; styrenes such styrene,chlorostyrene, methoxystyrene, methylstyrene, chloromethylstyrene,dichlorostyrene; acrylonitrile, methacrylonitrile, vinylpyrollidone,vinylimidazole, vinyl chloride, vinylidene chloride, methylvinylketone,vinylpyridine, vinylmethylpyridine, vinylethylpyridine,vinylmethylimidazole, the diacrylate of an aliphatic polyhydric alcohol,and the dimethacrylate of a polyhydric alcohol, with exemplarypolyhydric alcohols being the same as heretofore recited. One or two ormore of such comonomers can be copolymerized with the monomethacrylicacid ester or the monoacrylic acid ester.

In regard to the component ratio of the copolymers, it is preferred thatthe proportion of the monomethacrylic acid ester of the polyhydricalcohol or the monoacrylic acid ester of the polyhydric alcohol be morethan 50 mole percent, particularly more than mole percent.

The molecular weight of the polymer used in the neutralizationrate-controlling layer is usually more than 10,000, preferably from50,000 to 600,000.

As components used to form a graft polymer with the above esters used inthis invention, it is preferred to use gelatin, polyvinyl alcohol,polyacrylamide, carboxymethyl cellulose, starch, hydroxyethyl cellulose,etc.

The polymers used in the neutralization ratecontrolling layer can beprepared by any ordinary method such as a solution polymerization, agraft polymerization and the like. Practical examples of preparing thepolymers are illustrated below.

Synthesis Example 1 200 g of 2-hydroxyethyl methacrylate was added to amixed solvent of 550 ml of water and 550 ml of ethanol in a reactionvessel. After adding to the mixture 1 g of potassium persulfate and l gof sodium hydrogen sulfite, oxygen in the reaction vessel was purgedwith nitrogen gas and then the mixture was stirred for 4 hours at 60C.in the vessel.

The reaction product liquid was filtered and then poured in cold waterof (10 times the amount the filtrate), whereby the purified polymerprepared by the reaction was precipitated. The polymer was recovered anddried by means of a vacuum dryer. The amount of the polymer was 160g andthe molecular weight thereof was 350,000.

Synthesis Example 2 176 g of 2-hydroxyethyl methacrylate and 24 g ofacrylamide were added to a mixed solvent of 550 ml of water and 550 mlof ethanol in areaction vessel. After further adding to the mixture 0.8g of potassium persulfate and 0.8 g of sodium hydrogen sulfite, thevessel was purged with nitrogen gas and the mixture was stirred'for 3hours at C. The reaction product wasplaced in a pouch of a dialysisfilm, and after conducting dialysis for 15-20 hours in running water theproduct was dried by means of a freeze dryer. The amount of the productwas 197 g and the mean molecular weight thereof was 20,000.

Synthesis Example 3 300 g of 3hydroxypropyl methacrylate was added to amixed solvent of 400 ml of water and 800 ml of ethanol in a reactionvessel, and after adding further to the mixture 1 gofazobisisobutyronitrile the vessel was filled with nitrogen gas. Themixture was then stirred for 3.5 hours while maintaining the reactionsystem at a temperature of 70C. The reaction product liquid was filteredand poured in cold water times the amount thereof), whereby the polymerprepared by the reaction was precipitated. The polymer thus precipiatedwas recovered and dried by means of a vacuum dryer.

The amount of the polymer was 260 g and the mean molecular weightthereof was 570,000.

Synthesis Example 4 94 g of 2-hydroxyethyl acrylate was copolymerizedwith 106 g of 2-hydroxyethyl methacrylate in the same manner as inSynthesis Example 2. The amount of the copolymer thus prepared was 186 gand the mean molecular weight thereof was 230,000.

Synthesis Example 5 419 g of 2-hydroxyethyl methacrylate and 81 g ofmethyl-methacrylate were added to a mixed solvent of 500 ml of water and1500 ml of methanol in a reaction vessel. After further adding to themixture 1.5 g of henzoyl peroxide, the oxygen in the vessel was purgedwith nitrogen gas and then the mixture was stirred for 4.5 hours at 60C.The copolymer thus formed was purified and dried in the same manner asin Synthesis Example 3. The amount of the copolymer was 430 g and themean molecular weight thereof was 480,000.

Synthesis Example 6 50 g of hydroxyethyl cellulose was added to a mixedsolvent of 750 ml of water and 150 ml of ethanol and was dissolvedtherein at 60C. in a reaction vessel. After-purging the vessel withnitrogen gas, the temperature of the reaction system was raised to 75Cand then,

while adding dropwise a dispersion of 0.3 g of benzoyl perioxide in 50 gof 2-hydroxyethyl methacrylate through a dropping funnel, the reactionsystem was stirred for 4 hours at 75C. The reaction product was placedin a pouch of a dialysis membrane, and after conducting dialysis forhours in running water the product was dried by means of a freeze dryer.The amount of the polymer was 88 g.

The polymers for the neutralization rate-controlling layer used in thisinvention can be dissolved in various kinds of solvents and inparticular it is preferred to dissolve the polymers in a solvent such asethanol, me-

thanol-water, ethanol-water, acetone, acetone-water, methyl ethyl ketoneand methyl ethyl ketone-water.

' Furthermore, not only can the above one component a laminate with alayer of another polymer.

Examples of the polymer to be mixed with the afore said polymer for theneutralization rate-controlling layer of this invention or to be used asa layer combined ides such as polyethyleneoxide, polypropylene oxide andpolybutylene oxide, carboxymethyl cellulose, hydroxyethyl cellulose,p0ly-4-vinyl pyridine and polyvinyl acetate. The polymer to be mixedwith the neutralization rate-controlling polymers of this inventionpreferably has good miscibility. Accordingly, it is preferred to use apolymer which has a polarity similar to the neutralizationrate-controlling polymer.

When a mixture of the polymer of the monomethacrylic acid ester or themonoacrylic ester of the polyhydric alcohol and the other polymer asmentioned above is used the mixing ratio may be selected as desired butthe proportion of the other polymer is preferably about 50 percent orless.

It is also desirable that the dry thickness of theneutralizationrate-controlling layer composed of the polymer or polymersof the dye image receiving unit used in this invention be 3-20 microns,but the thickness may be varied properly according to the end usecontemplated.

As an image-receiving material, it is necessary to use a material whichhas a layer which is hydrophilic and which is capable of mordanting adiffusible dye. So, it is preferred to use a hydrophilic, basic andfilm-forming polymer or a hydrophilic and film-forming polymercontaining a basic polymer. As specific examples of the image-receivinglayer in this invention, a mixture of polyvinyl alcohol and poly-4-vinylpyridine as described in US Pat. No. 3,148,061 is preferably used, butother materials such as a partially acetalated product of polyvinylalcohol (degree of acetylation is no more than 20'percent) andtrialkylammonium benzaldehyde quaternary salt, a copolymer of vinylalcohol and N-vinylpyrrolidone (any copolymerization ratio can be used),a condensed acetalation product (from about 4 l to about 2 1 molarcondensate) of polyvinyl alcohol and poly-N-vinylpyrrolidone, and acondensed acetalation product (from about 4 1 to about 2 1 molarcondensate) of polyvinyl alcohol and 4- pyridine carboxy aldehyde canalso be used for the image-receiving layer. This testing is merelyexemplary of materials which meet the above general criteria.

The image-receiving material of this invention may further have, ifdesired, an intermediate layer for improving the adhesion between thesupport and the polymer layer and between the polymer layers themselves.Examples of materials used for the intermediate material are polyvinylalcohol, gelatin, carboxymethyl cellulose, hydroxyethyl cellulose,polyvinyl pyrrolidone, polyvinyl acetal, etc. The thickness of theintermediate layer is suitably from about lg. to about 10p..

By using the image-receiving material for a color diffusion transferprocess of this invention a sharp color image having less stains can beobtained.

As compared with the image-receiving material having a neutralizationrate-controlling layer composed of polyvinyl alcohol or a partiallyacetalated polyvinyl alcohol as described in US. Pat. No. 3,362,819, theimage-receiving material of this invention has various advantages, e.g.,the density of the images formed is higher and thus images of a widerange of gradation can be reproduced.

The polymer for the neutralization rate-controlling layer of thisinvention can be used for the neutralization rate-controlling layer ofimage-receiving materials for various types of color diffusion transferprocesses. For example, the polymer may be used for the neutralizationrate-controlling layers in a system using dye developers as described inU.S. Pat. No. 2,983,606 and also in a system using coupler developers asdescribed in U.S. Pat. No. 3,227,551.

The invention will, now be further illustrated in detail by severalexamples.

Example 1 The color image-receiving material, the alkali processingagent and the negative light-sensitive film were prepared in the mannerdescribed below. After imagewise exposure of the negativelight-sensitive film, the negative film was combined with the colorimagereceiving material, and the alkali processing agent (20C) insertedtherebetween so that the thickness of the layer of the alkali processingagent was about 200 microns, whereby the diffusion transfer processingwas conducted. The period required for the diffusion transfer processwas 2 minutes.

By the processing, a color image having less stains and having a highcolor density was obtained on the image-receiving layer.

A. Preparation of the image-receiving material:

A white baryta-coated layer having a polyethylene coating thereon wascoated with layers (a), (b), and (c) in that order.

a. Acid polymer layer:

,A 20 percent ethyl acetate solution of the monobutyl ester (meanmolecular weight 100,000) of the l l copolymer of maleic anhydride andvinyl methyl ether having the following unit formula was applied to thesupport in a dry thickness of 20 microns.

b. Neutralization rate-controlling layer:

20 g of the homopolymer of 2-hydroxyethyl methacrylate shown inSynthesis Example 1 was dissolved in a mixed solvent of 60 ml of acetoneand 20 ml of water and the solution was applied to the acid polymerlayer in a dry thickness of 8 microns.

c. Image-receiving layer:

6 g of polyvinyl alcohol (saponification degree 98 percent,polymerization degree 1800) and 3 g. of poly- 4-vinylpyridine (M.W.:70,00080,000) were dissolved in 150 ml of water containing 2 g ofglacial acetic acid and the solution was applied to the neutralizationratecontrolling layer in a dry thickness of 7 microns.

B. Preparation of alkali processing agent:

The alkali processing agent was prepared by blending the followingcomponents:

Natrosol 250 HR (Trade name, made by Hercules Incorporated) c.Preparation of negative film:

A .cellulose triacetate film having a gelatin undercoat was coated withthe following three layers as a monchromatic system. i

a. Dye developer layer:

10 g of l-phenyl-3-n-hexylcarboxyamide-4[p-2',5-dihydroxyphenethylphenylazo] 5-pyrazolone wasv dissolvedbutylacetanilide and 25 ml of cyclohexanone under heating. The solutionwas dispersed by emulsification in g of a 10 wt. percent aqueous gelatinsolution containing 8 ml of a 5 wt. percent aqueous solution of sodiumn-dodecylbenzenesulfonate. The emulsion was further mixed with 5 ml of a2 wt. percent aqueous solution of hydroxy-4,6-dichloro-S-triazine asahardening agent for gelatin, and then water was added to make the wholeamount of the emulsion 300 g. The aqueous emulsion was applied to thesupport in a dry thickness of 1.5 microns.

b. Silver halide photographic emulsion layer:

A silver iodobromide emulsion (7 mole percent silver iodide) containing3.5 X 10 mole of silver and 6.5 g of gelatin per 100 g of emulsion wasapplied to the dye developer layer in a dry thickness of 1.5 microns.

c. Gelatin protective layer:

5 g of 4'-methylphenyl hydroquinone was dissolved in a mixed solvent of10 ml of tri-o-cresyl phosphate and 10 ml of ethyl acetate and thesolution was dispersed by emulsification in 10 g of a 10 wt. percentaqueous gelatin solution containing 2 ml of a 5 wt. percent aqueoussolution of sodium n-dodecylbenzenesulfonate. Then, 100 ml of an aqueoussolution containing 10 g of the emulsion thus prepared and 5 ml of a 2wt. percent mucochloric acid solution as a hardening agent for gelatinwas applied to the silver halide emulsion layer in a dry thickness of 1micron.

On the other hand, an image-receiving material was prepared as acomparison sample in the same way as above except that a 10 wt. percentaqueous solution of polyvinyl alcohol (polymerization degree 1,800,saponification degree 98 percent) was applied in a dry thickness of 8microns in place of the homopolymer of 2- hydroxyethyl methacrylate asthe neutralization ratecontrolling layer of the image-receivingmaterial. When the diffusion transfer process as above was conductedusing the image-receiving material thus prepared, an image having lessstains was obtained but the color density of the image was only 60percent of the color density of the image obtained on theimage-receiving material of this invention as described above.

Example 2 An imagereceiving material was prepared in the same way as inExample 1 except that the copolymer prepared by copolymerizing2-hydroxyethyl methacrylate and acrylamide in a mole ratio of 4 l by theprocedure of Synthesis Example 2 was-used as the neutralizationrate-controlling layer. When the diffusion transfer was conducted usingthe image-receiving material as in Example 1, almost the same results asin Example 1 were obtained.

Example 3 An image-receiving material was prepared in the same way as inExample 1 except that the homopolyin a mixed solvent of 10 ml of N-nvmer of 3-hydroxypropyl methacrylate prepared in Synthesis Example 3 wasused as the neutralization ratecontrolling layer. In this case also,almost the same results as in Example 1 were obtained when the samediffusion transfer as in Example 1 was conducted.

Example 4 An image-receiving material was prepared in the same way as inExample 1 except that the copolymer of 2-hydroxyethyl acrylate and2-hydroxyethyl methacrylate prepared in Synthesis Example 4 was used forthe neutralization rate-controlling layer. When the same diffusiontransfer as in Example 1 was conducted using this image-receivingmaterial, almost the same results as in Example 1 were obtained.

Example 5 Example 6 An image-receiving material was prepared in the sameway as in Example 1 except that the graft polymer prepared bypolymerizing 2-hydroxyethyl methacrylate in a solution of hydroxyethylcellulose as in Syntehis Example 6 was used for the neutralizationratecontrolling layer and the solution of the polymer just after thepolymerization reaction was finished was applied as it was to the acidpolymer layer in a thickness of 8 microns. When the same diffusiontransfer process as Example 1 was conducted using this image-receivingmaterial, almost the same results as in Example 1 were obtained.

While the invention has been described in detail and with reference tospecific embodiments thereof, it will be apparent to one skilled in theart that various changes and modifications can be made therein with outdeparting from the spirit and scope thereof.

What is claimed is:

1. An image-receiving material for a color diffusion transfer processwhich comprises a support having thereon, in sequence, an acid polymerlayer, a neutralization rate-controlling layer, and an image receivinglayer, said neutralization rate-controlling layer comprising at leastone polymer selected from the homopolymer, the copolymer and the graftpolymer of the monomethacrylic acid ester of a polyhydric alcohol or themonoacrylic acid ester of a polyhydric alcohol.

2. The image-receiving material for a color diffusion transfer processas set forth in claim 1 in which said polymer is the homopolymer of themonomethacrylic acid ester of a polyhydric alcohol.

3. The image-receiving material for a color diffusion transfer processas set forth in claim 1 wherein said polymer is the copolymer of themonomethacrylic acid ester of a polyhydric alcohol and another vinylicmonomer copolymerizable therewith.

4. The image-receiving material for a color diffusion transfer processas set forth in claim 1 wherein said polymer is the graft polymer of themonomethacrylic acid ester of a polyhydric alcohol.

5. The image-receiving material for a color diffusion transfer processas set forth in claim 1 wherein said polymer is the homopolymer of themonoacrylic acid ester of a polyhydric alcohol.

6. The image-receiving material for a color diffusion transfer processas set forth in claim 1 wherein said polymer is the copolymer of themonoacrylic acid ester of a polyhydric alcohol and another vinylicmonomer copolymerizable therewith.

7. The image-receiving material for a color diffusion transfer processas set forth in claim 1 wherein said polymer is the graft polymer of themonoacrylic ester of a polyhydric alcohol.

8. An image-receiving material for a color diffusion transfer process asclaimed in claim 1 where said acid polymer has at least one carboxylgroup, sulfo group or a group hydrolyzable to a carboxyl group.

9. An image-receiving material for a color diffusion transfer process asclaimed in claim 9 where the acid polymer layer is 5-3O microns thick.

10. An image-receiving material for a color diffusion transfer processas claimed in claim 1 where said neutralization rate-controlling layercomprises the copolymer, and the acid ester comprises at least 50 molepercent of the copolymer.

11. An image-receiving material for a color diffusion transfer processas claimed in claim 1 where the molecular weight of the polymer is10,000 to 600,000.

12. An image-receiving material for a color diffusion transfer processas claimed in claim 1 where the thickness of the neutralizationrate-controlling layer is 320 microns.

13. An image-receiving material for a color diffusion transfer processas claimed in claim 1 where the polyhydric alcohol has 2 to 5 aliphatichydroxy groups of 2-12 atoms.

14. An image-receiving material for color diffusion transfer processwhich comprises a support having thereon, in sequence, an acid polymerlayer, a neutralization rate-controlling layer and an image receivinglayer, said image-receiving layer comprising a polymer containingpoly-4-vinylpyridine and said neutralization rate-controlling layercomprising at least one polymer selected from the homopolymer, thecopolymer and the graft polymer of the monomethacrylic acid ester of apolyhydric alcohol or the monoacrylic acid ester of a polyhydricalcohol.

1. AN IMAGE-RECEIVING MATERIAL FOR A COLOR DIFFUSION TRANSFER PROCESSWHICH COMPRISES A SUPPORT HAVING THEREIN, IN SEQUENCE, AN ACID POLYMERLAYER, A NEUTRALIZATION RATECONTROLLING LAYER, AND AN IMAGE RECEIVINGLAYER, SAID NEUTRALIZATION RATE-CONTROLLING LAYER COMPRISING AT LEASTONE POLYMER SELECTED FROM THE HOMOPOLYMER, THE COPOLYMER AND THE GRAFTPOLYMER OF THE MONOMETHYACRYLIC ACID STER OF A POLYHYDROXALCOHOL OR THEMONOACRYLIC ACID ESTER OF A POLYHYDRIC ALCOHOL
 2. The image-receivingmaterial for a color diffusion transfer process as set forth in claim 1in which said polymer is the homopolymer of the monomethacrylic acidester of a polyhydric alcohol.
 3. The image-receiving material for acolor diffusion transfer process as set forth in claim 1 wherein saidpolymer is the copolymer of the monomethacrylic acid ester of apolyhydric alcohol and another vinylic monomer copolymerizabletherewith.
 4. The image-receiving material for a color diffusiontransfer process as set forth in claim 1 wherein said polymer is thegraft polymer of the monomethacrylic acid ester of a polyhydric alcohol.5. The image-receiving material for a color diffusion transfer processas set forth in claim 1 wherein said polymer is the homopolymer of themonoacrylic acid ester of a polyhydric alcohol.
 6. The image-receivingmaterial for a color diffusion transfer process as set forth in claim 1wherein said polymer is the copolymer of the monoacrylic acid ester of apolyhydric alcohol and another vinylic monomer copolymerizabletherewith.
 7. The image-receiving material for a color diffusiontransfer process as set forth in claim 1 wherein said polymer is thegraft polymer of the monoacrylic ester of a polyhydric alcohol.
 8. Animage-receiving material for a color diffusion transfer process asclaimed in claim 1 where said acid polymer has at least one carboxylgroup, sulfo group or a group hydrolyzable to a carboxyl group.
 9. Animage-receiving material for a color diffusion transfer process asclaimed in claim 9 where the acid polymer layer is 5-30 microns thick.10. An image-receiving material for a color diffusion transfer processas claimed in claim 1 where said neutralization rate-controlling layercomprises the copolymeR, and the acid ester comprises at least 50 molepercent of the copolymer.
 11. An image-receiving material for a colordiffusion transfer process as claimed in claim 1 where the molecularweight of the polymer is 10,000 to 600,000.
 12. An image-receivingmaterial for a color diffusion transfer process as claimed in claim 1where the thickness of the neutralization rate-controlling layer is 3-20microns.
 13. An image-receiving material for a color diffusion transferprocess as claimed in claim 1 where the polyhydric alcohol has 2 to 5aliphatic hydroxy groups of 2-12 atoms.
 14. An image-receiving materialfor color diffusion transfer process which comprises a support havingthereon, in sequence, an acid polymer layer, a neutralizationrate-controlling layer and an image receiving layer, saidimage-receiving layer comprising a polymer containingpoly-4-vinylpyridine and said neutralization rate-controlling layercomprising at least one polymer selected from the homopolymer, thecopolymer and the graft polymer of the monomethacrylic acid ester of apolyhydric alcohol or the monoacrylic acid ester of a polyhydricalcohol.